le clercq



Jan. 31, 1956 L J. E cLERcQ 2,732,590

METHOD OF AND APPARATUS FOR PRODUCING MICRO-DIMENSIONED CERAMIC TILE Filed Sept. 20, 1952 4 Sheets-Sheet 1 Tro/QNEM Jan. 31, 1956 L. J. LE cLl-:RcQ 2,732,590

METHOD OF AND APPARATUS FOR PRODUCING MICROnDIMENSIONED CERAMIC TILE 4 sheets-sneer 2 Filed sept. 2o,v 1952 l1. IL

I N V EN T 0R. r E CLEQCQ /ff/ Jl T TOQNE Y.

Jan. 3l, 1956 1 J. LE cLERcQ' 2,732,590

' METHOD OF AND APPARATUS FOR PRODUCING l MICRO-DIMENSIONED CERAMIC TILE 4 Sheets-Sheet 3 Filed Sept. 20, 1952 IN V EN TOR.

Q. C m M J.. N 0 E L Jan. 3l, 1956 y l.. J. LE cLERcQ 2,732,590

METHOD OF AND APPARATUS F OR PRODUCING MICRO-DIMENSIONED CERAMIC TILE I /Wrly 9' INVENTOR.

LEON r LE C25-@CQ METHD F AND APPARATUS FOR PRODUCING MICRO-DIMENSINED CERAMIC TILE Calif., assignor to Gladding, Los Angeles, Calif., a corporation of This invention relates to a method and apparatus for Precisely and accurately dimensioning rectangular or square ceramic tile in order to provide tile adapted to be readily assembled in a pattern having uniform straight and continuous joint lines. The invention particularly relates to a means and method for producing tile having spacing means on two contiguous edge faces, and having plain` edge faces contiguous and opposite thereto, ground into precisely spaced parallel relation therewith for uniformly spacing adjacent tile, such tile being described and claimed in my copending application tiled of even date herewith.

Appearance of a wall composed of a` plurality of assembled rectangular or square tile is judged not only by the particular selection of the color of the tile, but also by the uniformity of the spacing of adjacent tile to provide straight, continuous, even, uniformly-wide joint lines. In such a pattern it is apparent that joint lines form an important decorative part of the entire pattern since they frame `each of the individual tile arranged on the wall. While eachv individual tile may appear to be square and 'of identical size and dimension, when such tile are assembled in a pattern with other tile, slight discrepancies in dimension are accentuated and emphasized. The accentuation of size difference is quickly detected by the irregular joint lines formed. irregular joint lines give the appearance of sloppy workmanship and seriously detract from the appearance of the wall no matter how beautiful may be the color of the tile surface.

Tile bodies are formed by pressing in suitable dies to accurate, predetermined dimensions and in precise squared relationship. The size of tile manufactured under present techniques depends upon several factors such as wear o'f pressing dies, shrinkage characteristics of ceramic tile bodies including moisture content of the pressed body, variant characteristics of clays utilized, position of the pressed clay bodyV in the kiln, the firing to which the clay body is subjected, etc. Numerous,

production controls are employed preceding firing to regulate these several factors. However, ultimate tile size is finally determined by the control exercised during fir ing. After tiring, the size of tile is not subjected to further appreciable change.

However, under even the most rigidly pursued production controls, a pressed, accurately squared green tile body may become slightly wedge-shaped or out-of-'square an'd vary in outermost dimensions between 0.25 and 0.70 inch depending upon the path of the tile followed through the kiln. Such tile may be classied into groups of small (variance of .025 to .040 inch), regular (.040 to .055) and large (.055 to .070) so that the possibilities of a large size tile being included in a group of small tile is virtually eliminated. The method of classifyingthe dierent sized tile is important because it is a sampling method and it is commvn practice to include .regular'tile with small tile, orzregul'ar tile with Ylarge tile. s

When plain edged tile which includes sizes of different groups are laid upon a wall, the first course is accurately 2,732,590 Patented Jan. 3.1, 1956 aligned by using jack lines so that the bottom edges Vof the tile lie in a plane. Each course thereafter must be aligned by means of a jack line and the uniformity of the joint width separating the tile courses and each tile in a course depends entirely upon the skill and care of the workman. 5

One purported solution to the problem of making uni.- form joint lines has been that of providing in the pressing operation a pair of spaced projections on each edge. face of a tile, the projections on each edge face being identi cally positioned. Each spacing projection is adapted to abut a corresponding spacing projection on an adjacent tile and since the spacing projections are pressed to a precise uniform depth of one-half the joint width, the abut ment of spacing projections on adjacent tile will purportedly provide a joint of uniform width. However, due to the dimensional changes of a tile during firing, it is still usual to have tile of different dimensions as measured between the extremities of opposed spacing projections in variance from about .025 to .070 inch as nieutioned.

Thus, the use of spacing projections on each edge face of a tile has only partially solved the problem of providing uniform joint lines. When using such tile, an in?l staller may place from three to ve courses upon a wail before rejacking or realigning the tile courses in order to install a tile wall of presentable appearance. Beyond ve courses, the accumulated error in dimension dilferentials becomes readily apparent to an observers eyes and detracts from the wall appearance. Thus again, skill and workmanship of the installer must be relied upon -to provide a presentable tile Wall.

The method of this invention also considerably affects production operations for making at tile bodies. Elimi' nation or simplification is achieved of several production steps whichmay be used in the making of tile having spaced projections on each edge face thereof. These production savings occur because the tile size is determined after tiring by grinding tired tile to precise size and shape. Since the control of size by firing is no longer necessary in the production of the tile of this invention, the production techniques may be considerably simplified.Y

The effect on production of tile made in accordance with the method and apparatus of this invention may perhaps best be described by comparing certain specific steps of present exemplary operations for manufacturing a tile body and the proposed new production operation for manufacturing a ceramic tile body of this invention. At the present time, after tile bodies have been pressed and fettled, they may be stacked in bungs in face-to-face relation. The face-.to-face relationship' is employed in order to facilitate uniformity of firing and to prevent impression of a back-ribbed face on the front face due to the Weight of a column of tile bodies which is forined in a second stacking operation. In the new operation, the pressed tile may be tirst stacked in furniture in face'- to-back relationship. In the second stacking operation, at the present time, initial bungs may be stacked to provide a larger bling and no furniture is used. In the new operation, a sec'- ond stacking is not required.

ln present operations when the bungs of tile have passed ti rough the kiln, pairs of tile in face-tolface relation must be separated from adjacent pairs of tile (known as picking) by manually inserting a knife between corners of pairs of tile. Later, each pair of tile which is in faceto-face relation is separated `and tested (known as ring ing) by dropping each individual tile on a dat metal plate. In the; new operation, Such separation or picking and such. ringing is not required.

The present invention contemplates a means and mthod for producing a precisely dimensioned ceramic tile body which is designed to facilitate construction and installation of a tiled surface, reduce labor costs in the manufacture of the tile, provide a more attractive and uniform tiled surface, and also simplify production techniques and operations. v

The primary object of this invention is to provide a means and method for producing as an article of manufacture ceramic tile designed to be easily assembled into a pattern with uniform joint lines and precisely dimensioned after firing.

An object of this invention is to provide a means and method for producing microdimensioned ceramic tile having pairs of opposed edge faces, one face of each pair having integral therewith tile spacing projections the width of -a joint line to be formed and the other face of each pair having tile contacting plain edge faces lying in planes parallel to and precisely spaced from the planes of the other faces of said pairs.

Another object of this invention is to provide a method of precisely dimensioning such tile bodies wherein the n tile bodies are automatically handled and processed in a continuous production line and wherein contiguous plain edge faces may be ground to accurately dimension the tile.

A further object of this invention is to provide a method for producing such tile wherein a plurality of tile to be dimensioned are advanced in a selected path in a straight line in a horizontal plane and are irrnly held in desired selected position during a grinding operation whereby the tile is precisely microdimensioned.

The invention contemplates an apparatus for producing tile as above described wherein novel conveyor means are arranged to advance and to hold tile in selected position during a grinding operation.

A further object of this invention is to design and provide apparatus whereby a plurality of tile bodies arranged in series may be accurately and precisely ground to selected dimension. Still another object of this invention is to provide a conveyor means having tile holders for accurately positioning tile held thereby and provided with means cooperative with the tile and tile holders to maintain the tile in a settled path of travel through a grinding zone.

Generally speaking, this invention contemplates a method wherein a plurality of tile bodies in series are advanced by feed conveyor means and transferred to a novel conveyor means which includes a plurality of tile holders adapted to receive and accurately position the tile before the tile are advanced through a grinding zone. The latter conveyor means includes means for maintaining the tile in selected nonchangeable position while the tile holders are advanced through a tile grinding zone so that an edge face of each tile may be presented to a grinding means and whereby pairs of opposed edge faces of the tile are formed into selected spaced parallel relationship. The apparatus includes means for fettling or beveling the ground edge face of the tile so as to provide acorner or edge at the decorative surface thereof which is uniform in appearance with the two contiguous nonground edge faces. The apparatus include means for automatically and continuously handling the tile so that they may be transferred and placed on a different conveyor means for advancement through a second grinding zone for grinding the other plain edge face into parallel, precisely spaced relationship with its opposite edge face.

Other objects and advantages of this invention will be readily apparent from the drawings and description, in which an exemplary apparatus embodying this invention is shown.

In the drawings:

j Fig. 1 is a side view of an apparatus embodying this invention for grinding selected edge faces of a tile body.

Fig. 2 is a top view of the Vapparatus shown in Fig. l.

Fig. 3 is a transverse sectional view taken in the vertical planes indicated by line vIII-III of Fig. 2.

Fig. 4 is a transverse sectional view taken in the vertical plane indicated by line IV-IV of Fig. 2.

Fig. 5 is a fragmentary end view taken from plane indicated by line V-V of Fig. 1.

Fig. 6 is a fragmentary enlarged, longitudinal sectional view taken in the planes indicated by line VI--VI of Fig. 3.

Fig. 7 is a fragmentary enlarged, transverse sectional view taken in the plane indicated by line VII-VII of Fig. 6.

Fig. 8 is a plan view of a tile body dimensioned by the apparatus yand method of this invention.

Fig. 9 is a diagrammatic view showing the sequence of operations performed on a tile body by the apparatus and method of this invention.

To facilitate understanding of the apparatus and method of this invention, attention is directed first to Fig. 8 wherein an exemplary tile 11 precisely dimensioned thereby is shown. Tile 11 is of at, rectangular or square form and may have a decorative surface defined by pairs of opposed parallel edge faces 12 and 13. The one edge face 12 of each pair is provided with tile spacing elements 14 and the other edge face 13 of each pair is plain and uninterrupted. The plain edge faces 13 are ground into precise spaced parallel relation to the plane passing through the opposed edge face 12 or the outermost extremity of the elements 14. The elements 14 are virtually the Width of a joint line to be formed and the planes of contiguous edge faces 12 lie at right angles to each other.

Generally speaking, the apparatus of this invention indicated at 15 comprises a frame structure 16 upon which may be supported a roller chain conveyor means, generally indicated at 17, provided with tile holders 18 adapted to receive a tile 11 to be processed from a belttype feed conveyor 2t). The conveyor 17 includes means generally indicated at 21 for holding and maintaining tile holders 18 in a selected, virtually non-yielding path ot travel past grinding means 22 supported by the frame structure at one side of the conveyor means 17. After tile 11 has been ground along one plain edge face 13 by grinding means 22, the corner of ground edge face 13 may be beveled by a fettling means 23 disposed adjacent one end of conveyor means 17. Transfer means 24 are provided at the discharge end of conveyor means 17 for transferring tile 11 to a third conveyor means 25 which may transport the tile 11 to a second apparatus 15 for grinding the second contiguous plain edge face 13 of the tile or, if processing is completed, to a stacking table.

The frame structure 16 may comprise any suitable arrangement of upstanding spaced legs 26 formed of structural metal members for carrying longitudinally extending, transversely spaced outwardly facing channel members 26a. A ilat horizontal mounting plate 27 is supported above the top edge of channels 26a by spaced stub legs 27a and an upwardly extended frame leg 26 (Fig. 3). The plate 27 extends virtually the length of conveyor means 17 and transversely covers a substantial in. termediate portion of frame structure 16. Suitable gussets 28 or other bracing means may be employed to provide a rigid frame structure.

As illustrated, the feed conveyor means 20 is only fragmentarily shown in Fig. l and has a discharge end positioned adjacent to conveyor means 17 and in alignment therewith. Feed conveyor 20 may comprise any suitable flexible endless belt 30 mounted for continuous rotation over end drums 31, only one of which is shown. Each end drum 31 may be carried by a suitable shaft 32 mounted on bearing means 33 secured to a suitable frame which may include frame structure 16. Driving means for feed conveyor 20 is not illustrated and may consistv of any well-knowndriving means for belt conveyors, such as an electric motor and a pulley drive connection between the feed conveyor'and the motor. 1- v l The conveyor 17 may comprise a plurality ofl longin a'l' movement in a' straight horizontal path'by a longitu lly exte ndin g` vertical guide rail 40 (Fig. 7) disposed below the` top lay and secured to mounting plate 2 7 by longitudinally spaced angle brackets 41 andassociated securing screw` bolts 42. T he rollersof chain ootaet, as at 43,' thetop edge of said guide rail 40 fori rollingl contact therealong in a horizontal plane. The ends of the" gfuide rail terminate in proximity to the Spwketwheelsfe `de t'also'if each tileholder 18 may be best seen in' s.' 2 and 7. Each tile holder l18 comprises a flat rec n gular normally horizontal plate portion having integrally formed thereon, at two contiguous edge niargifnsh pstanding shoulders 4 6 and 47. The inner faces of said shoulders 46 and 47V are disposed in planes at right angles to each other. Shoulder 46 is` formed along the tfailing edge marginof be piovided'with a pair of spaced vertical slots 48,'adapted to accommodate tile spacing elements 14 provided on one the tile` vholder 18 and may edge face 12'. of a tile 11 when the tile is carried in the holder.

The other opstanding shoulder `47 is formed along an 'geimargin'of the holder onthe side of the `conveyor v1'7 opposite to grinding means 22. Shoulder 47 is provided with' an vinte"rrn'ediately: disposed longitudinally eXtending depression or recess 50 'on its inner face to accommodate spacing elements 1 4 providedon the` edge faceV 1 2' of tile 1;'1 rcontiguous to the edge face opposing shoulder v46, Wliei av tile 1 1 is prop erly positioned in tileliolder 1 8 portions of contiguous edge faces 12 areadapted to abut, as at 52 `and 53 (Fig. 2) the opposed inner facel portions of shoulders 46 and 47.

Edge margins of the flat plate portion 45 opposite to shoulders 46 dd 47 are not provided ,with shoulders but' are open and unobstructed. The distance between the edges of the open edge margins of the tile holder to the inner faces of theupstandingslioulders and 47 is less"A than the corresponding dimensions of a tile 1 1 hel d middels, .Thus a fue Ircariidiir, ede` nii-gine including plain edge faces 13`pr 1 ytiiid'unobstrt ed edges of hat :late portion 45; The sidevidly projecting 'edge niaifgin of `ti1e" 1 -1 is' dddpfjd toj be ground by giiiidiiig means gz whilofihe' forwardly projecting loading dgoj ma'frgiii of'di ri is "d` i to becontactedby spaced rearwardlyeit" 'ding 54 (Fig. 6) for urging tilell longitudinally w clly for snug s`houlder`"6: f Ced :Sii fris means 54 hay Q'ch'infsaseh: al portion 55 adapted to= be secured against e face' ofV the iitplateI portion 4 5 by suitable nut 4 iid' sc `w iiians 56. Each spiingineans 54 also in` el'iide's a r'erxitfai'dly and upwardly directed end portion 5 7 which extends between spaced tile hold 13u/hen dis sed in tHe'uppe'rlay of the conveyor means' for contat witli the ldiiig edge f a tile 11 as above meti- Boii die iiordor- 1s iiidybo connected to die c iia'i* 3s ent td its leading transverse edge bya pair`` o flaterl spaced ai1g"le brackets 58 having depending legs di`s pose Y oppositesides of chain 3 5 and secured thereto onveyoi'j means 17 may bie provided anuxabutment against the inner faces of iliary endless beltjmeans 60 supported by and between spaeedjchannelszoaaiid'below chain 35. The belt means i@ may be rded aboutend drums-,61 einem ,are 62 s'ipportedin ba'riiigsss, The auxiliary bolt mean 6o may'coinprise'av flexible `endless belt' 64 is supported along a substantial portion` o f its upper lay bya rigidt horizontal membero carriedby upwardly and inwardly bent brackets ,66 `secured to the bottoni' face of the dut; board channelmember 26d. Thus, as tile holdersl 18 progress rearwardly along the lower layof the conveyor 17, they are supported for movement in" a substantially horizontal plane and de tlection of the lower lay' of chain ssdiie to die wig'hfof die die holders is iiiiiiiiiiized, thereby redueing stretching and the imposition of unl desirable s tressesonsaidchain. Means' 21 for supporting ,the plurality of tile holders 18 ina substantially unyielding rigid straight horizontal path of travel as'theymove through grinding Vzone for precisely dimensining thel tile may include a plurality of longitudinally closelyspced aligned lguide rollers 68 paralleling said path of trayel Iand adapted to contact', as d t 69;r oiiter side faces of shoulders 47 of the tile holders. Assiiowiiin Fig. 2 the' lino of 'rollers ss ooiiiao't ai ioasl vfourtile holders and the' diameter of the' rollers is such that four or more rollers maycoiita'ct each tile holder.

Each roller 6'3 IriayY be mounted for rotation on a veri tical aigle 7l) threadedly carried by a longitudinally entendi ingside bar 71V spaced above mounting plate 2 7 by longitudinally Vspaced feet 7 2., Each axle 70 carries a securing nut 73. They line of rollers-68 antifrictionally guide the die hoidoisdiioogiij Vuio griiidiiig zond past the' grinding mas, and resist nytrahsversely acting" forces which might tend to laterally displace the tile holders outboardly offheaiiiaratuf Onthe sidefof conveyor means 17,` the tile holdersL may be positivelyA guided iii their selected path by a p ar al lel line of a plurality of antifrictionr'olle'rs 75 @t when; fue" am@ danse as faire: 68. ,Rulers is are' adapted to rollingly contact an outer side face o'f a depending edge"v liange ,76 provided on each tile holder Eaeh'roller 75 is carried a vertical s liaft 72 l` which is supported from vthe top elenient of a'rgenerallyQ-seetioried; longitudinally extending ni'ofmjoor 79tnebottoii1 oie'iieiit of the c sectional modiber 79 being adapted to be secured t0 mounting plate 277 by a plurality of spaced screw bolts 80. The line' c'if rollers 75` resis"t la `l displacement of tile holders 18 toward Iii 1152.1., `for preventing tilting ofeach tile holder about doitaet; as t" 83; againstV the bottom edge faceof dependL g e"7 6 of ea i i tile holder. Each roller 82 is car` by a 8 4 which is supported by a'n upstandin'g, longitudinally eirteriding rigid-member 85 which may be seeu'redto the C section member 79l by a plurality of stud -vi/hieh draw lower portions of member 85 in t abutment as at 87 withthe edge face of the lower elerrient ofthe C section member `79.

,To resist possibleupward displacement of a tile body a, tile'holde'r 18 during al grinding operation-.`

lrrlity o f resiliently downwardlybiased wheels 9 supported above tile holders 18 for rolling pressure cont'aetj with'-the topsurfaeeofatile as at 9i. The Whe s` Q Ufin'ay be" made of any suitable rubber composilas 'not to mar the surface ofr the tile and may be fried by aX1es 9 2, each receivedy within laterally 'lrgnedfdownwarclly opening slots 9 3 formed in depending 'n'ge's" ofan inverted generally U section, longitudinally entendingmember V94. The flanges of member 9 4 vertically arranged bores 95 opening into slots la adapted `to coil springs 96. rl`he lower end o'fe is adaptedtobear against anend axle The member 94 may be supported by a pair of longitudinally spaced, inwardly facing C-shaped brackets 97 secured by screw bolts 98 to mounting plate 27. A tie bar 99 may connect brackets 97 above the member 94. Suitable bolts may secure member 94 to the brackets 97 in overhanging aligned relation to the chain 3S.

As each tile holder progresses through the grinding zone and past grinding means 22, each tile holder, for a substantial portion of its longitudinal movement in the top lay of conveyor means 17, will be rigidly and nonyieldingly held against lateral displacement, vertical downward displacement, and resiliently held against vertical upward displacement. Thus each tile body 11 carried by tile holders 18 is moved past the grinding means for grinding in a predetermined, precisely maintained, selected path of travel so that each tile may be accurately ground along the sidewardly projecting exposed edge face.

Means for driving conveyor 17 may include an electric motor 100 positioned adjacent one end of frame structure 16. A chain drive 101 may connect the drive shaft of the motor to a sprocket or gear 102 supported on an inboardly extended portion of the adjacent shaft 37 which carries sprocket wheel 36 at one end of the conveyor 21. The extended portion of shaft 37 may be supported in bearing means 103 carried by the inboard channel member 26a.

At the opposite end of conveyor 17 means are provided for driving the auxiliary belt means 60 in synchronism with conveyor 17. The other shaft 37 may be extended to carry a sprocket wheel for engagement with a drive chain 104, said drive chain having engagement at 105 with a sprocket wheel 106 carried on an inboard extension of the adjacent shaft 62 of belt means 60. The chain 104 may extend downwardly for inmeshed engagement with a gear wheel 107 supported below the inboard channel 26a.

Means for adjusting the tension of the auxiliary belt means 60 and for vertically adjusting the receiving end of belt means 60 may include a lever means 108 pivoted at 109 to adjacent gusset members 28 and adjusted by means of an arcuate slot 110 and a bolt and nut assembly 111 cooperable with said slot and carried intermediate the ends of the lever means 108. The opposite end of lever means 108 may be pivotally connected to the adjacent shaft 62.

Grinding means 22 (two of which are shown, only one being described in detail) may comprise any suitable type of disc grinder having a rotatable head 115 adapted to carry a grinding disc 116, the peripheral margin of said disc 116 being capable of positioning adjacent to the path t of tile holders 18. The head 115 may be supported on a motor shaft 117 adapted to be rotated by any suitable driving means carried within the housing, generally indicated at 118. The housing 118 may be pivotally supported on spaced side frames 119 carried by a carriage 120 adapted to be moved along transversely extending ways 121 secured to the mounting plate 27 at one side of the conveyor means 21. The carriage 120 is precisely incrementally reciprocally moved by means of Verniertype micrometer actuating and indicating means generally indicated at 122, said means being of well-known type. The grinding means 22 may be advanced so that the grinding face of the grinding disc 116 may be moved into precise selected spaced parallel relationship with respect to the inner face of the longitudinally extending shoulder-47 on the tile holders and thus, said grinding disc may be accurately positioned so that each tile 11 may be ground to a predetermined precise dimension in width and in parallel relation.

It may be desirable to employ the exemplary two grinding means so that the first grinding means may roughly grind the opposed edge of a tile to approximate dimension, and the second grinding means be employed to precisely finish grind the roughly ground edge face of a tile body to the precise selected dimension. lt is understood that one or more grinding means may be employed as desired.

After tile 11 has been ground along one exposed plainv edge face 13 by grinding means 22, the top corner of the newly formed edge face may be beveled to conform to the beveled edges of the nonground faces by a fettling means, generally indicated at 23 (Fig. 4). The fettling means 23 may comprise an endless sanding belt 125 supported from spaced parallel cylinders 126 carried by shafts V127 which may be journaled in spaced, upwardly inclined support members 128. The lower shaft 127 may be extended to carry a pulley 129 carrying one end of a drive belt 130 connected by pulley 131 to the output shaft 132 of an electric motor 133. One supporting member 128 may include a base 134 having a flange 135 secured to mounting plate 27. The opposite parallel member 128 is carried by shafts 127 and an intermediate spacing sleeve and bolt assembly 136.

Means for transferring tile 11 from the feed conveyor 20 to the tile holder conveyor 17 may include utilization of an air jet or blast from an air nozzle 137 (Fig. l) carried by an air hose 138 adjacent to the discharge end of feed conveyor 20. As selectively positioned tile 11 with their back faces up follow belt 30 downwardly about the drum 31, the tile slip downwardly and are picked up by a tile holder 18. The leading edge of tile 11 drops against the trailing shoulder 46 of the tile holder and as the tile holder begins to move upwardly and away from said conveyor 20, an air blast pushes the tile over and against the at plate portion of the tile holder.

ln order to initially properly position the tile 11 within the holder, laterally spaced tapered guide rollers 140 disposed adjacent to sprocket wheel 36 contact the side shoulder 47 of the holder and the exposed opposite plain edge face of the tile. The tapered roller 140 contacting the exposed edge face of the tile is adapted to urge the tile laterally so that the opposite edge face 12 abuts the inner faces of side shoulder 47. Immediately following the lateral positioning action of the guide rollers 140, the tile holders 18 complete their curved path of travel about sprocket 36 and begin to move in a straight horizontal path of travel along the top lay of the conveyor 17. As the tile holders become horizontally aligned, the spring means 54 of preceding tile holders engage leading edge faces of following tile and press said tile rearwardly against the trailing shoulders 46. The tile is thus automatically positioned and held in snug abutmenty against shoulders 46 and 47.

Means for transferring tile 11 from the tile holder conveyor means 17 to a third conveyor means 25 for transporting the tile to a second grinding apparatus or to a stacking table may include a curved chute member 142 adapted to receive a tile after it has once turned over caused by following of the tile holder about the end sprocket 36. The tile 11 with back face up then slides down chute 42 for deposit upon endless belt means 143 of the conveyor 25. The flip-flop of the tile upon dis-l charge positions the tile so that it may be transferred to a second grinding machine in the manner described above for transferring tile bodies from feed conveyor 20 to conveyor 17. It is understood other means and methods may be used to transfer the tile to and from the tile holder conveyor means 17.

In the method and apparatus of this invention, tile may be pressed slightly oversize as measured between opposite edge faces 12 and 13, such as .060 inch, and with tile spacing elements 14 formed upon contiguous edge faces 12, the other edge face 13 of each pair being plain. After tile has been so pressed, it may be stacked in furniture with the contiguous edge faces 12 bearing the tile spacing elements 14 arranged in a like and corresponding position, the spacing elements serving to identify the corner formed by contiguous edge faces 12. The pressed tile thus arranged in furniture may be tired in well-known manner.

The purpose of uniformly arranging the tile with respect to the corner formed and identified by contiguous tissievs' @fa ,12 ecrs @dus tiri. a .It Italia Bii `found t the posi` ioinvof `thetileA in kiln with respect to th sourcefuolf `heat affects the degree of distortion of va Vous portions of thel tile.v Qutlof-square relationship f certain edge" faces of a` pressed tile body is caused by firing effects; LTheref'iref, vselectively positioning o'f the' pressed tile bodies 4in th'vmfurni'ture andjn the kiln maintains tlri'e pressed V90"l 'relatioslipgbetweenthe contiguous edge faces 12 virtually accurate whilethe angular relationship 0f the ontisrlsus rese faces 1.3 ,frminsthe pposite corner may vary froin9ilf. 4This variance is, cor-l rected during the vof said edge faces N13., While the tile spacing elementsnll 'alcird'readyV identification of a selected corner, it is vunderstootl that other reference marks may be used to identify a selected corner for particularly selected position tiring.

After rang, the vfired ai@ may' be piace-agita selecfea spaced 'recrationship upon Ythelvfeed conveyor 20 with vthe back surface up. Here againV Vthe contiguous vedge faces bearingtlie tile spacing elernen 11 serve as' a reference identificati@ for` a corner` kour the tite S9 that it may be properly selectively positioned on the feed conveyor. The immediately following steps in grinding and han; dling the tile have been substantiallydescribed above and briefly in clide transferring of the tile from the feed conveyor to the tile holder conveyor 17, positioning tile 11 in tile holders 18 so that the contiguous edge faces 12 abut against the contiguous shoulders 46 and 47 of the tile holderand anedge face 13 is sidewardly projecting exposed relation maintaining the tile holders 18 and tile 11 carried thereby in a virtually nonyielding, straight horizontal pathY of travel through a grinding zone adjacent to' and including the grinding means 22, grinding the exposed edge face 13 of tile 11 by the grinding means, fet'tling thetop edge of the newly gro'und edge face, and then transferring tile 11 to another conveyor means. The latter conveyor means may advance the tile through a second grinding operation for grinding the other edge face of the tile, or it may transport the tile 11 to a table for stacking and further processing'. l

vIt) will thus be readily apparentA from the above description that a method has been disclosed for producing tile having precisely microdimensioned, spaced parallel pairs of edge faces, and that one of each pair of edge faces is provided with tile spacing elements of a width of a joint to be formed for accurately and easily assembling tile of this invention into a pattern with uniform, straight continuous joint lines. The apparatus of the in- Vvention discloses a tile holder conveyor means which is adapted to be maintained in a virtually lateral, longitudinal, and vertical nonyielding relation so that as it moves through a grinding zone, tile carried thereby can be ground to precise accurate dimensions and one edge face may be ground into precise parallel relationship with the opposed edge face.

It is understood that various modifications and changes may be made in the apparatus and method of this invention which may fall within the spirit of this invention and all such modifications and changes coming Within the scope of the appended claims are embraced thereby.

I claim:

l. A method of producing precisely dimensoined rectangular ceramic tile, comprising the steps of: pressing unburned clay tile body to form pairs of parallel opposite edge faces, one face of each pair having tile spacing elements thereon and the other face being plain, said pressed body having the dimension between edge faces of each pair greater than ultimate desired dimension and with contiguous edge faces at right angles; moving the unburned tile body through a kiln with the corner of the body defined by contiguous edge faces bearing the tile spacing elements selectively positioned with respect to heat flow in the kiln to avoid distortion of said corner pla .el parallel nto' said0 grinding` Vsaid l fce inte precisa sraed; parallel relaties to ,thjl oppor; edge face; and'then advancing said tile ,inV sele ed sil til'n :straight: nonyielding path' of travel' th a se 'd grinding zofneg'and grinding thelqthe'r pla Ieige fatte" precise, Sipcd, prll'enl relti'll'td its Opp sulaf ',C'rmicitilmprians the stese 0? bt an unburned clay tile body to frrnp 'rs of l site edge faces, one facelof ch'p elements thereon anrduthe of each pair greater than ultimate desired dirne1 l With, amitie@dus4 @dse faces at r'isht anales: moving, he unburned tile body through ajkllnmvvith tli corner of bedr' farmed by contiendra, edge.. faces ble ibs til 5p C? ingfe'le`rr'1er-1tsj` positioned `with respect to'lh ,now in je kiln to' avoid.distortionof` said fclorner during" firing, ad; vancing sele 't'velyrpositionedA tired tile'a straight, ing' ding pa 'fztravfel` through a grinding 'zone with plain edge facgexpo'seq and vvith the Qppdsiteds'ej f held longitudinally extending plane parallel to s d pathpan'd grinding said: jegqiosedI e ge"k facevinto precise, SPaCd: 153131161 .rlion. t? the, @if j Sife dig? fa,

3.y method of producing preciselypdirnensione nl Ceramic,A Atile'icomprising the `steps of: pressing uiibiirned c lay tilegb'ody to p'airspof parallelop sit edge faces, one face' of each pair havi'ri'gtiley sp i elements thereon and theothejr face' being plain, and contiguous edge faces at right angles; passing the unburned tile body through a kiln withjfa, selectedgcoijner thereof positionedfwith` respect toh'eat tiovvuin the to avoidwdistfftion of said selected` corinfer;l advancing s l ctivjelyV positioned'iired tile in a straighfgliionyieldihg' of travel' through a `grindingzonewith a plain edge s e'll and' withy the opposite, edge face held in K nall'ymextendingplne paralleltsaid path; and gfrmding said e poseded'geface intfo precise, spaed, pari f. 1,911, t0. the OPPOSfe eier? fece"- 4. A' method' of making precisely dimensiiie'd reic-4 tangular tile, comprising: pressing a rectangular unburned clay tile body with oversize dimensions and with at least one corner formed by contiguous edge faces lying at right angles; providing a reference identification for said one corner of said body; passing the unburned tile body through a kiln with said one corner of said tile body positioned with respect to heat ilow in the kiln to avoid distortion of said one corner during tiring; advancing the oversized tired tile with said identified corner in a selected position and with an opposite edge face of the tile exposed; and then grinding said exposed edge face into precise, spaced, parallel relation to the opposite edge ace.

5. In an apparatus for grinding one edge face of a ceramic tile into selected, spaced, parallel relation to the opposite edge face, the combination of: a frame structure; a conveyor means carried by the frame structure and adapted to receive tile from a feeding means, said conveyor means comprising an endless means carried by the frame and having a top lay and a bottom lay; a plurality of closely spaced tile holders carried by the endless means, each tile holder including upstanding tile positioning means adjacent one side edge and a contiguous transverse edge, said tile positioning means including a spring element projecting away from said transverse tile positioning means and adapted to contact an edge face of an adjacent tile for urging said adjacent tile against transverse tile positioning means on the adjacent holder; guiding means carried by said frame structure adjacent tain said tile holders and tile carried thereby in a straight, nonyielding path of travel in said plane through a grinding zone; grinding means carried by the frame structure at one side of the top lay of the conveyor for grinding contact with the exposed edge faces of tile carried in the holders; and drive means for said conveyor means.

6. An apparatus as claimed in claim wherein means are carried by the frame structure at the receiving end of the conveyor means to initially laterally position tile received by said conveyor means, said positioning means including a pair of laterally spaced opposed tapered rollers mounted for rotation about inclined axes and spaced apart to contact a side face of a tile holder and an edge face of a tile carried thereby.

7. In an apparatus for precisely dimensioning flat, thin polygonal tile, the combination of: a conveyor means; means carried by the conveyor means for holding individual tile in separate relation; positioning means for immovably holding each tile on said holding means including an upstanding face lying in a longitudinally extending plane parallel to the path of travel of said conveyor through a grinding zone; a transverse shoulder lying in a plane pelpendicular to said path of travel, and a resilient element extending away from said transverse shoulder and toward an adjacent holder and adapted to urge a tile held by said adjacent holder against a transverse shoulder on said adjacent holder; means for positively maintaining said holding means in said path of travel; and grinding means including a grinding face selectively positioned in spaced parallel relation to the upstanding face on said positioning means whereby individual tile carried by said holding means may have one edge face ground into precisely parallel spaced relation to said face on the positioning means.

8. In an apparatus for precisely dimensioning tile, the combination of: a conveyor means; a plurality of generally at, normally horizontally disposed tile holders carried by the conveyor means for movement through a grinding zone; positioning means on each holder adapted to position a tile with one longitudinal edge face exposed and extending beyond said holder and lying parallel to the direction of movement; a contiguous edge face lying transversely to said direction of movement; and means at said grinding zone in engagement with each holder and adapted to engage a. tile held by each holder during movement through said zone for maintaining said holders and tile in a selected path of travel and restraining against vertical and lateral deviation from said path; grinding means including a grinding face vertically disposed parallel and at one side of said selected path of travel of said holders and tile and adjustably movable into selected position therewith for grinding said exposed edge face into precise spaced parallel relation to the opposite edge face of said tile; and drive means for the conveyor means.

v 9. A method of making precisely dimensioned rectangular tile comprising: pressing an unburned clay tile body to form pairs of parallel opposite edge faces, one face of each pair having tile spacing elements thereon and the other face being plain, and with contiguous edge faces at right angles; passing the unburned tile body through a kiln with a selected corner thereof positioned with respect to heat flow in the kiln to avoid distortion of said selected corner; advancing selectively positioned red tile in a path of travel through a grinding zone with a plain edge face exposed; and grinding said exposed edge face into precise spaced parallel relation to the opposite edge face.

References Cited in the file of this patent UNITED STATES PATENTS 713,256 Werra Nov. 11, 1902 1,156,574 Adderson Oct. 12, 1915 1,220,201 Danner Mar. 27, 1917 1,453,175 Perrault Apr. 24, 1923 1,797,342 Hitchcock Mar. 24, 1931 1,908,029 Larson May 9, 1933 1,920,076 Happel July 25, 1933 1,960,289 Simmons May 29, 1934 2,025,474 Quigg Dec. 24, 1935 2,205,628 Morrison June 25, 1940 2,298,955 Mason Oct. 13, 1942 FOREIGN PATENTS 258,926 Switzerland June 1, 1949 503,553 Germany Aug. 6, 1930 517,141 Great Britain Ian. 22, 1940 

